THE CELLULAR STRUCTURE OF PLANTS 53 



Cytoplasmic sac: the term used to designate the cytoplasm 

 of the cell when it takes the form of a sac lining the cell 

 wall and bounding the central water vacuole. 



Nucleus : a denser differentiated protoplasmic body within the 

 cell bounded by the nuclear membrane. 



Nudeolus: a darker dense mass of protoplasm within the 

 nuclear cavity. It is usually surrounded in plant cells by 

 a nuclear vacuole. 



Plastids : differentiated grains or bodies of cytoplasm of 

 different color and function. 



